Solid state lighting (SSL) light bulb assemblies, e.g. light emitting diode (LED) based light bulb assemblies, are currently replacing GLS (general lighting service) or incandescent lamps. SSL devices typically comprise a driver circuit and/or power converter in order to convert electric power from a mains supply to DC (direct current) electric power suitable for an SSL light source comprised within the SSL device (e.g. an array of LEDs).
An SSL assembly may comprise a plurality of SSL devices, e.g. for generating differently colored light or for generating white light from SSL devices which emit differently colored light. A driver circuit for such an SSL assembly typically comprises a plurality of power converters for driving the plurality of SSL devices, respectively. Alternatively, the electrical power produced by a power converter may be directed to the different SSL devices of the plurality of SSL devices using one or more switches.
In SSL assemblies, flickering of the SSL light source should be avoided. To improve the light quality, capacitors are used for stabilizing the energy supply to the SSL light sources. However, large capacitors typically increase the overall dimensions of the SSL assembly and may lead to a decreased lifetime. Specifically, large electrolytic capacitors tend to have high failure rates and may limit the lifetime of the entire SLL assembly. Thus, it is preferable that small capacitors such as e.g. ceramic or film capacitors are used instead of large electrolytic capacitors.
The present document addresses the mentioned technical problems and provides small, cost and power efficient SSL assemblies which show a stable start-up behavior.